You are an apple wholesale buyer. Larger "Fireside" apples (larger by weight per apple) command higher retail prices per kg. You got offers of the same price per kg for Fireside apples from Farms A and B.

The apple weights from each Farm have a normal distribution with standard deviation = 15 grams. Each of the 10 randomly chosen apples from each farm are weights, and a t-test is run with 99% confidence level to compare the mean apple weights from the two farms.

Unknown to you, the average weight of apples from Farm A is 6 grams lower than that from Farm B.

(1) What is the chance that you can make the right call that the mean weight of apples from Farm B is higher than that from Farm A?

(2) If you want to have the chance to make the right call higher than 70%, how many apples from each farm at minimum do you need to weigh?